Electrocatalysis of Oxygen Using Water Soluble Metal Porphyrins and Chemically Modified Porphyrin Electrodes.
Abstract
Primary effort was devoted to the study of oxygen reduction using wateroluble iron and cobalt porphyrins, namely, iron and cobalt tetrakis (N-methyl-4-pyridyl)porphyrin. These porphyrins with the metal in the +3 oxidation state can be electrochemically reduced to the divalent state which can then reacted with oxygen. In the case of the iron containing porphyrin, oxygen was reduced at a bimolecular rate of ca. 1 x 10 to the minus 7th power 1/m/s to hydrogen perioxide which was then reduced rapidly to water. A mechanistic scheme was postulated for the reduction and using experimentally determined parameters, current-potential curves were simulated. Good agreement between the experimental and computer calculated current-potential curves supported the proposed scheme. Cross-correlation between optical, electrochemical and magnetic circular dichroism results have provided axial ligation, dimerization and spin state information of the ferric and ferrous tetrakis (n-methyl-4-pyridyl)porphyrins. Glassy or graphitic carbon electrodes were rendered catalytic by the incorporation of iron porphyrin derivatives infinity e.g. iron tetra-(o-amino-phenyl)porphyrin and iron tetra-(N(2-hydroxyethyl)pyridyl)porphyrin summation in thin polymeric films adhering to the carbon. The extent of oxygen reduction to hydrogen peroxide and water depended on the amount of iron porphyin.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1983
- Accession Number
- ADA136062
Entities
People
- T. Kuwana
Organizations
- Ohio State University